4 ms·
You wouldn't want true random numbers anyways. If you're encrypting it, then you'll want to decrypt it later. That means you'll need the random data you used ag
by syrrim 9y ago
You wouldn't want true random numbers anyways. If you're encrypting it, then you'll want to decrypt it later. That means you'll need the random data you used again. If you had a secure channel over which to send or store the random data, then you could just use that channel to send or store the plaintext itself (note that the random data will be the same length as the plaintext). Such a system could only be useful if the cryptographic key was shorter than the plaintext. So it would have to be a deterministic RNG, and you would only need the seed and the ciphertext in order to decrypt.
Also, if someone has acccess to the hardware, then you're screwed. No one would bother wasting time with a hairdryer. If the plaintext was on your harddrive, they would just grab that and run.
- IncRnd 9y agoI think you missed the point of the comment, which wasn't about physical possession of a computer. You also make assumptions, such as chips being inside the computer, when they can in fact be in an outside environment-based RNG. The hairdryer example is the canonical and prototypical weakness in that particular type of "rng". I'll try to be explicit about that in the future.
- pkolaczk 9y agoI didn't write anything about environment-based RNG. RNG must be deterministic and seeded by preshared encryption key. One point of using a cryptographically secure RNG is that it should not be possible to learn the seed by observing the output of the RNG without bruteforcing the key.